A total synthesis of the alkaloid gephyrotoxin, a muscarinic antagonist available in only milligram quantities from skin extracts of the Neotropical frog Dendrobates histrionicus, is proposed. A synthetic pathway has been devised which will permit the synthesis of substituted cis-decahydroquinoline and indolizidine structures that have tentatively been assigned to other dendrobatid alkaloids. During the course of the proposed gephyrotoxin synthesis, a protocol is established for applying the concept of A-1,3 strain to complex stereochemical problems in alkaloid synthesis. The possibility of applying this concept to a variety of alkaloid families is discussed.